1 // SPDX-License-Identifier: BSD-3-Clause
2 /*
3  * reloc_x86_64.c - position independent x86_64 ELF shared object relocator
4  * Copyright (C) 1999 Hewlett-Packard Co.
5  * Contributed by David Mosberger <davidm@hpl.hp.com>.
6  * Copyright (C) 2005 Intel Co.
7  * Contributed by Fenghua Yu <fenghua.yu@intel.com>.
8  *
9  * All rights reserved.
10  */
11 
12 #include <common.h>
13 #include <efi.h>
14 #include <elf.h>
15 
_relocate(long ldbase,Elf64_Dyn * dyn)16 efi_status_t EFIAPI _relocate(long ldbase, Elf64_Dyn *dyn)
17 {
18 	long relsz = 0, relent = 0;
19 	Elf64_Rel *rel = 0;
20 	unsigned long *addr;
21 	int i;
22 
23 	for (i = 0; dyn[i].d_tag != DT_NULL; ++i) {
24 		switch (dyn[i].d_tag) {
25 		case DT_RELA:
26 			rel = (Elf64_Rel *)
27 				((unsigned long)dyn[i].d_un.d_ptr + ldbase);
28 			break;
29 		case DT_RELASZ:
30 			relsz = dyn[i].d_un.d_val;
31 			break;
32 		case DT_RELAENT:
33 			relent = dyn[i].d_un.d_val;
34 			break;
35 		default:
36 			break;
37 		}
38 	}
39 
40 	if (!rel && relent == 0)
41 		return EFI_SUCCESS;
42 
43 	if (!rel || relent == 0)
44 		return EFI_LOAD_ERROR;
45 
46 	while (relsz > 0) {
47 		/* apply the relocs */
48 		switch (ELF64_R_TYPE(rel->r_info)) {
49 		case R_X86_64_NONE:
50 			break;
51 		case R_X86_64_RELATIVE:
52 			addr = (unsigned long *)(ldbase + rel->r_offset);
53 			*addr += ldbase;
54 			break;
55 		default:
56 			break;
57 		}
58 		rel = (Elf64_Rel *)((char *)rel + relent);
59 		relsz -= relent;
60 	}
61 
62 	return EFI_SUCCESS;
63 }
64